1. Technical Field
The present invention relates to a printed circuit board, including a supporting base element in the shape of a heat removing metal plate or panel, one side of which has a laminate layer with at least one printed circuit.
2. Background Art
The manufacture of such printed circuit boards have caused problems because of the requirement that the heat removing plate must be electrically insulated. Efforts have been made inter alia to use circuit boards having a core of anodized aluminium, i.e. with an electrically insulating metal oxide film. Aluminium or steel plates covered with different types of resins have also been tested. These tests have not been very successful, for instance because of the formation of pores in the insulating film, thereby causing short-circuits between the metal plate and the electric circuit. If, on the other hand, the insulating film is made sufficiently thick in order to ensure that no pores are present, the ability of conducting away the heat from the circuit components will decrease.